Apr 2023
Petroleum geochemistry plays crucial roles in assessing conventional and unconventional petroleum systems from exploration to production phases. In many cases, their techniques provide the only solutions to both research and operation problems. The current study highlights new integrated techniques that employed advanced organic and inorganic geochemical techniques that were integrated with basin modeling and palynological in four Middle Eastern basins in northern and northwestern Africa as well as in the Arabian peninsula. The geochemical techniques include total carbon (organic and inorganic), Rock Eval pyrolysis, and biomarkers, carbon isotopes, pyrolysis-gas chromatography, X- ray fluorescence (XRF) and organic microscopy. The four basins represent three different shallow marine environments from inner shelf (deltaic), to middle shelf to outer shelf. Detailed geochemical analyses enabled good understanding of the common geochemical characteristics of each depositional environment.
New geochemical proxies for source rock quality were developed based on integrated geochemical parameters to predict source rock quality. For example, a new organic sulfur proxy can provide insights on source rock kinetics. Another example is the technique of time-lapse geochemistry, which extracts valuable insights from produced gas and oil over time for production allocation of gas and oil. The depositional environments and the best potential of the carbonate source rocks were investigated in details by utilizing total organic carbon and pyrolysis along with oxygen and carbon isotope chemostratigraphy. Meanwhile, produced liquid hydrocarbons and the residue hydrocarbons extracted from the reservoir(?)/source rocks by utilizing the high-resolution organic solvent extractions were studied and correlated in numerous intervals within the studied section. It appears that the high production intervals are consistent with the high production potentials suggested by the carbon and oxygen isotope chemostratigraphy. The promising results help allocate the best production potential.
This study has provided a new integrated approach to connect the best source rock potential to the production sweet zones. In addition, it highlighted the rich hydrocarbon zones that require additional fracking job. In summary, the study elucidated the new approach to evaluate petroleum system that helped tackle operational challenges in both exploration and production phases.
Dr. Bandar Ghassal is the Geochemistry Unit supervisor and geological consultant in Saudi Aramco EXPEC Advanced Research Center of Saudi Aramco. He has more than 18 years of experience in the technical and leadership domains in Saudi Aramco and Petro-Hunt Middle East companies. Bandar earned his MSc degree from the University of Utah and his Doctoral degree in petroleum geochemistry from the RWTH Aachen University. He earned his MSc and PhD in Geology from The University of Utah and RWTH Aachen University respectively. He co-led high-profile projects such as seepage exploration program, low-enthalpy geothermal energy and recently natural hydrogen. He published several papers, book chapters and conference abstracts on various geoscience and engineering topics. He recently published a new book entitled “Advances in petroleum source rock characterizations: integrated methods and case studies. He was also recognized as best leader in EXPEC Research Center of Saudi Aramco in 2022.